In order to cope with the demands of high density computing, groups of targets in, for example, blade server environments may need to be coupled to one another. Serial Attached Small Computer System Interface (Serial Attached SCSI, or, SAS) technology may address storage connectivity issues due to the low cost and efficient interconnectivity thereof. A SAS environment may be associated with a datacenter. The main components of the SAS environment may be host controllers, adapters, expanders and/or multiplexers. The aforementioned main components of the SAS environment may be buried deep in the system such that there may be no external access thereto.
The only interface to the main components (e.g., interface to “Just a Bunch of Disks” (JBODs) associated therewith) in the SAS environment may be the SAS link therebetween. There may be management interfaces therein but, again, access thereto may be difficult. If a main component of the SAS environment requires debugging (e.g., debugging firmware/software associated therewith), it may be difficult to access debugging interfaces associated therewith. Although at a development board level the requisite connectors for debugging may be available, the end systems at the datacenter of deployment may not have access thereto.
Tracing may be a common method to enable debugging of the firmware/software associated with the main components of the SAS environment. Traces may include small bits of code written into the firmware/software that are configured to detect the program flow. A common method of firmware tracing includes allocating a trace buffer (e.g., circular buffer) in the firmware/software to which the trace points may be logged. The trace buffer may be exported out of the deeply buried components through different transport mechanisms (e.g., Trivial File Transfer Protocol (TFTP), Telnet, SCSI read buffer, Universal Asynchronous Receiver/Transmitter (UART)).
The aforementioned method of firmware tracing may require allocation of the trace buffer in a processor (e.g., Random-Access Memory (RAM)) associated with the main component of the SAS environment, which may impose restrictions on the amount of trace buffer allocation. An accurate time-stamping of trace data may be required of the firmware/software, for which the system may lack the ability. The processor enabled tracing may not be used in end products associated with the datacenter due to the lack of debugger headers and/or physical access restrictions imposed due to the enclosure design thereof. The software implementation of the trace buffer may tend to affect real-time performance and/or may consume critical memory resources associated with the main component(s) of the SAS environment.